diff --git a/packages/web_benchmarks/CHANGELOG.md b/packages/web_benchmarks/CHANGELOG.md
index cb26fd04c5f..5641ddfb3ab 100644
--- a/packages/web_benchmarks/CHANGELOG.md
+++ b/packages/web_benchmarks/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 1.1.0
+
+* Adds `computeAverage` and `computeDelta` methods to support analysis of benchmark results.
+
 ## 1.0.1
 
 * Adds `parse` constructors for the `BenchmarkResults` and `BenchmarkScore` classes.
diff --git a/packages/web_benchmarks/README.md b/packages/web_benchmarks/README.md
index cc38fc92cea..ce98a22b194 100644
--- a/packages/web_benchmarks/README.md
+++ b/packages/web_benchmarks/README.md
@@ -13,3 +13,45 @@ app's code and assets. Additionally, the server communicates with the browser to
 extract the performance traces.
 
 [1]: https://github.com/flutter/packages/blob/master/packages/web_benchmarks/testing/web_benchmarks_test.dart
+
+# Analyzing benchmark results
+
+After running web benchmarks, you may want to analyze the results or compare
+with the results from other benchmark runs. The `web_benchmarks` package
+supports the following analysis operations:
+
+* compute the delta between two benchmark results
+* compute the average of a set of benchmark results
+
+<?code-excerpt "example/analyze_example.dart (analyze)"?>
+```dart
+import 'dart:convert';
+import 'dart:io';
+
+import 'package:web_benchmarks/analysis.dart';
+
+void main() {
+  final BenchmarkResults baselineResults =
+      _benchmarkResultsFromFile('/path/to/benchmark_baseline.json');
+  final BenchmarkResults testResults1 =
+      _benchmarkResultsFromFile('/path/to/benchmark_test_1.json');
+  final BenchmarkResults testResults2 =
+      _benchmarkResultsFromFile('/path/to/benchmark_test_2.json');
+
+  // Compute the delta between [baselineResults] and [testResults1].
+  final BenchmarkResults delta = computeDelta(baselineResults, testResults1);
+  stdout.writeln(delta.toJson());
+
+  // Compute the average of [testResults] and [testResults2].
+  final BenchmarkResults average =
+      computeAverage(<BenchmarkResults>[testResults1, testResults2]);
+  stdout.writeln(average.toJson());
+}
+
+BenchmarkResults _benchmarkResultsFromFile(String path) {
+  final File file = File.fromUri(Uri.parse(path));
+  final Map<String, Object?> fileContentAsJson =
+      jsonDecode(file.readAsStringSync()) as Map<String, Object?>;
+  return BenchmarkResults.parse(fileContentAsJson);
+}
+```
diff --git a/packages/web_benchmarks/example/analyze_example.dart b/packages/web_benchmarks/example/analyze_example.dart
new file mode 100644
index 00000000000..bf2721ac594
--- /dev/null
+++ b/packages/web_benchmarks/example/analyze_example.dart
@@ -0,0 +1,35 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// #docregion analyze
+import 'dart:convert';
+import 'dart:io';
+
+import 'package:web_benchmarks/analysis.dart';
+
+void main() {
+  final BenchmarkResults baselineResults =
+      _benchmarkResultsFromFile('/path/to/benchmark_baseline.json');
+  final BenchmarkResults testResults1 =
+      _benchmarkResultsFromFile('/path/to/benchmark_test_1.json');
+  final BenchmarkResults testResults2 =
+      _benchmarkResultsFromFile('/path/to/benchmark_test_2.json');
+
+  // Compute the delta between [baselineResults] and [testResults1].
+  final BenchmarkResults delta = computeDelta(baselineResults, testResults1);
+  stdout.writeln(delta.toJson());
+
+  // Compute the average of [testResults] and [testResults2].
+  final BenchmarkResults average =
+      computeAverage(<BenchmarkResults>[testResults1, testResults2]);
+  stdout.writeln(average.toJson());
+}
+
+BenchmarkResults _benchmarkResultsFromFile(String path) {
+  final File file = File.fromUri(Uri.parse(path));
+  final Map<String, Object?> fileContentAsJson =
+      jsonDecode(file.readAsStringSync()) as Map<String, Object?>;
+  return BenchmarkResults.parse(fileContentAsJson);
+}
+// #enddocregion analyze
diff --git a/packages/web_benchmarks/lib/analysis.dart b/packages/web_benchmarks/lib/analysis.dart
new file mode 100644
index 00000000000..73b5d6e78c5
--- /dev/null
+++ b/packages/web_benchmarks/lib/analysis.dart
@@ -0,0 +1,121 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'package:collection/collection.dart';
+import 'server.dart';
+
+export 'src/benchmark_result.dart';
+
+/// Returns the average of the benchmark results in [results].
+///
+/// Each element in [results] is expected to have identical benchmark names and
+/// metrics; otherwise, an [Exception] will be thrown.
+BenchmarkResults computeAverage(List<BenchmarkResults> results) {
+  if (results.isEmpty) {
+    throw ArgumentError('Cannot take average of empty list.');
+  }
+
+  final BenchmarkResults totalSum = results.reduce(
+    (BenchmarkResults sum, BenchmarkResults next) => sum._sumWith(next),
+  );
+
+  final BenchmarkResults average = totalSum;
+  for (final String benchmark in totalSum.scores.keys) {
+    final List<BenchmarkScore> scoresForBenchmark = totalSum.scores[benchmark]!;
+    for (int i = 0; i < scoresForBenchmark.length; i++) {
+      final BenchmarkScore score = scoresForBenchmark[i];
+      final double averageValue = score.value / results.length;
+      average.scores[benchmark]![i] =
+          BenchmarkScore(metric: score.metric, value: averageValue);
+    }
+  }
+  return average;
+}
+
+/// Computes the delta for each matching metric in [test] and [baseline], and
+/// returns a new [BenchmarkResults] object where each [BenchmarkScore] contains
+/// a [delta] value.
+BenchmarkResults computeDelta(
+  BenchmarkResults baseline,
+  BenchmarkResults test,
+) {
+  final Map<String, List<BenchmarkScore>> delta =
+      <String, List<BenchmarkScore>>{};
+  for (final String benchmarkName in test.scores.keys) {
+    final List<BenchmarkScore> testScores = test.scores[benchmarkName]!;
+    final List<BenchmarkScore>? baselineScores = baseline.scores[benchmarkName];
+    delta[benchmarkName] = testScores.map<BenchmarkScore>(
+      (BenchmarkScore testScore) {
+        final BenchmarkScore? baselineScore = baselineScores?.firstWhereOrNull(
+            (BenchmarkScore s) => s.metric == testScore.metric);
+        return testScore._copyWith(
+          delta: baselineScore == null
+              ? null
+              : (testScore.value - baselineScore.value).toDouble(),
+        );
+      },
+    ).toList();
+  }
+  return BenchmarkResults(delta);
+}
+
+extension _AnalysisExtension on BenchmarkResults {
+  /// Sums this [BenchmarkResults] instance with [other] by adding the values
+  /// of each matching benchmark score.
+  ///
+  /// Returns a [BenchmarkResults] object with the summed values.
+  ///
+  /// When [throwExceptionOnMismatch] is true (default), the set of benchmark
+  /// names and metric names in [other] are expected to be identical to those in
+  /// [scores], or else an [Exception] will be thrown.
+  BenchmarkResults _sumWith(
+    BenchmarkResults other, {
+    bool throwExceptionOnMismatch = true,
+  }) {
+    final Map<String, List<BenchmarkScore>> sum =
+        <String, List<BenchmarkScore>>{};
+    for (final String benchmark in scores.keys) {
+      // Look up this benchmark in [other].
+      final List<BenchmarkScore>? matchingBenchmark = other.scores[benchmark];
+      if (matchingBenchmark == null) {
+        if (throwExceptionOnMismatch) {
+          throw Exception(
+            'Cannot sum benchmarks because [other] is missing an entry for '
+            'benchmark "$benchmark".',
+          );
+        }
+        continue;
+      }
+
+      final List<BenchmarkScore> scoresForBenchmark = scores[benchmark]!;
+      sum[benchmark] =
+          scoresForBenchmark.map<BenchmarkScore>((BenchmarkScore score) {
+        // Look up this score in the [matchingBenchmark] from [other].
+        final BenchmarkScore? matchingScore = matchingBenchmark
+            .firstWhereOrNull((BenchmarkScore s) => s.metric == score.metric);
+        if (matchingScore == null && throwExceptionOnMismatch) {
+          throw Exception(
+            'Cannot sum benchmarks because benchmark "$benchmark" is missing '
+            'a score for metric ${score.metric}.',
+          );
+        }
+        return score._copyWith(
+          value: matchingScore == null
+              ? score.value
+              : score.value + matchingScore.value,
+        );
+      }).toList();
+    }
+    return BenchmarkResults(sum);
+  }
+}
+
+extension _CopyExtension on BenchmarkScore {
+  BenchmarkScore _copyWith({String? metric, num? value, num? delta}) =>
+      BenchmarkScore(
+        metric: metric ?? this.metric,
+        value: value ?? this.value,
+        delta: delta ?? this.delta,
+      );
+}
diff --git a/packages/web_benchmarks/lib/src/benchmark_result.dart b/packages/web_benchmarks/lib/src/benchmark_result.dart
index 445dc939489..ac80c747345 100644
--- a/packages/web_benchmarks/lib/src/benchmark_result.dart
+++ b/packages/web_benchmarks/lib/src/benchmark_result.dart
@@ -10,17 +10,26 @@ class BenchmarkScore {
   BenchmarkScore({
     required this.metric,
     required this.value,
+    this.delta,
   });
 
   /// Deserializes a JSON object to create a [BenchmarkScore] object.
   factory BenchmarkScore.parse(Map<String, Object?> json) {
-    final String metric = json[_metricKey]! as String;
-    final double value = (json[_valueKey]! as num).toDouble();
-    return BenchmarkScore(metric: metric, value: value);
+    final String metric = json[metricKey]! as String;
+    final double value = (json[valueKey]! as num).toDouble();
+    final num? delta = json[deltaKey] as num?;
+    return BenchmarkScore(metric: metric, value: value, delta: delta);
   }
 
-  static const String _metricKey = 'metric';
-  static const String _valueKey = 'value';
+  /// The key for the value [metric] in the [BenchmarkScore] JSON
+  /// representation.
+  static const String metricKey = 'metric';
+
+  /// The key for the value [value] in the [BenchmarkScore] JSON representation.
+  static const String valueKey = 'value';
+
+  /// The key for the value [delta] in the [BenchmarkScore] JSON representation.
+  static const String deltaKey = 'delta';
 
   /// The name of the metric that this score is categorized under.
   ///
@@ -31,11 +40,18 @@ class BenchmarkScore {
   /// The result of measuring a particular metric in this benchmark run.
   final num value;
 
+  /// Optional delta value describing the difference between this metric's score
+  /// and the score of a matching metric from another [BenchmarkResults].
+  ///
+  /// This value may be assigned by the [computeDelta] analysis method.
+  final num? delta;
+
   /// Serializes the benchmark metric to a JSON object.
   Map<String, Object?> toJson() {
     return <String, Object?>{
-      _metricKey: metric,
-      _valueKey: value,
+      metricKey: metric,
+      valueKey: value,
+      if (delta != null) deltaKey: delta,
     };
   }
 }
@@ -53,7 +69,7 @@ class BenchmarkResults {
       final List<BenchmarkScore> scores = (json[key]! as List<Object?>)
           .cast<Map<String, Object?>>()
           .map(BenchmarkScore.parse)
-          .toList();
+          .toList(growable: false);
       results[key] = scores;
     }
     return BenchmarkResults(results);
diff --git a/packages/web_benchmarks/pubspec.yaml b/packages/web_benchmarks/pubspec.yaml
index 7c090ca62ad..117d8dd246e 100644
--- a/packages/web_benchmarks/pubspec.yaml
+++ b/packages/web_benchmarks/pubspec.yaml
@@ -2,13 +2,14 @@ name: web_benchmarks
 description: A benchmark harness for performance-testing Flutter apps in Chrome.
 repository: https://github.com/flutter/packages/tree/main/packages/web_benchmarks
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+web_benchmarks%22
-version: 1.0.1
+version: 1.1.0
 
 environment:
   sdk: ">=3.2.0 <4.0.0"
   flutter: ">=3.16.0"
 
 dependencies:
+  collection: ^1.18.0
   flutter:
     sdk: flutter
   flutter_test:
diff --git a/packages/web_benchmarks/test/src/analysis_test.dart b/packages/web_benchmarks/test/src/analysis_test.dart
new file mode 100644
index 00000000000..852cb4c6408
--- /dev/null
+++ b/packages/web_benchmarks/test/src/analysis_test.dart
@@ -0,0 +1,330 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'package:flutter_test/flutter_test.dart';
+import 'package:web_benchmarks/analysis.dart';
+
+void main() {
+  group('averageBenchmarkResults', () {
+    test('succeeds for identical benchmark names and metrics', () {
+      final BenchmarkResults result1 = BenchmarkResults(
+        <String, List<BenchmarkScore>>{
+          'foo': <BenchmarkScore>[
+            BenchmarkScore(metric: 'foo.bar', value: 6),
+            BenchmarkScore(metric: 'foo.baz', value: 10),
+          ],
+          'bar': <BenchmarkScore>[
+            BenchmarkScore(metric: 'bar.foo', value: 2.4),
+          ],
+        },
+      );
+      final BenchmarkResults result2 = BenchmarkResults(
+        <String, List<BenchmarkScore>>{
+          'foo': <BenchmarkScore>[
+            BenchmarkScore(metric: 'foo.bar', value: 4),
+            BenchmarkScore(metric: 'foo.baz', value: 10),
+          ],
+          'bar': <BenchmarkScore>[
+            BenchmarkScore(metric: 'bar.foo', value: 1.2),
+          ],
+        },
+      );
+      final BenchmarkResults average =
+          computeAverage(<BenchmarkResults>[result1, result2]);
+      expect(
+        average.toJson(),
+        <String, List<Map<String, Object?>>>{
+          'foo': <Map<String, Object?>>[
+            <String, Object?>{'metric': 'foo.bar', 'value': 5},
+            <String, Object?>{'metric': 'foo.baz', 'value': 10},
+          ],
+          'bar': <Map<String, Object?>>[
+            <String, Object?>{'metric': 'bar.foo', 'value': 1.7999999999999998},
+          ],
+        },
+      );
+    });
+
+    test('fails for mismatched benchmark names', () {
+      final BenchmarkResults result1 = BenchmarkResults(
+        <String, List<BenchmarkScore>>{
+          'foo': <BenchmarkScore>[BenchmarkScore(metric: 'foo.bar', value: 6)],
+        },
+      );
+      final BenchmarkResults result2 = BenchmarkResults(
+        <String, List<BenchmarkScore>>{
+          'foo1': <BenchmarkScore>[BenchmarkScore(metric: 'foo.bar', value: 4)],
+        },
+      );
+      expect(
+        () {
+          computeAverage(<BenchmarkResults>[result1, result2]);
+        },
+        throwsException,
+      );
+    });
+
+    test('fails for mismatched benchmark metrics', () {
+      final BenchmarkResults result1 = BenchmarkResults(
+        <String, List<BenchmarkScore>>{
+          'foo': <BenchmarkScore>[BenchmarkScore(metric: 'foo.bar', value: 6)],
+        },
+      );
+      final BenchmarkResults result2 = BenchmarkResults(
+        <String, List<BenchmarkScore>>{
+          'foo': <BenchmarkScore>[BenchmarkScore(metric: 'foo.boo', value: 4)],
+        },
+      );
+      expect(
+        () {
+          computeAverage(<BenchmarkResults>[result1, result2]);
+        },
+        throwsException,
+      );
+    });
+  });
+
+  test('computeDelta', () {
+    final BenchmarkResults benchmark1 =
+        BenchmarkResults.parse(testBenchmarkResults1);
+    final BenchmarkResults benchmark2 =
+        BenchmarkResults.parse(testBenchmarkResults2);
+    final BenchmarkResults delta = computeDelta(benchmark1, benchmark2);
+    expect(delta.toJson(), expectedBenchmarkDelta);
+  });
+}
+
+final Map<String, List<Map<String, Object?>>> testBenchmarkResults1 =
+    <String, List<Map<String, Object?>>>{
+  'foo': <Map<String, Object?>>[
+    <String, Object?>{'metric': 'preroll_frame.average', 'value': 60.5},
+    <String, Object?>{'metric': 'preroll_frame.outlierAverage', 'value': 1400},
+    <String, Object?>{'metric': 'preroll_frame.outlierRatio', 'value': 20.2},
+    <String, Object?>{'metric': 'preroll_frame.noise', 'value': 0.85},
+    <String, Object?>{'metric': 'apply_frame.average', 'value': 80.0},
+    <String, Object?>{'metric': 'apply_frame.outlierAverage', 'value': 200.6},
+    <String, Object?>{'metric': 'apply_frame.outlierRatio', 'value': 2.5},
+    <String, Object?>{'metric': 'apply_frame.noise', 'value': 0.4},
+    <String, Object?>{'metric': 'drawFrameDuration.average', 'value': 2058.9},
+    <String, Object?>{
+      'metric': 'drawFrameDuration.outlierAverage',
+      'value': 24000,
+    },
+    <String, Object?>{
+      'metric': 'drawFrameDuration.outlierRatio',
+      'value': 12.05,
+    },
+    <String, Object?>{'metric': 'drawFrameDuration.noise', 'value': 0.34},
+    <String, Object?>{'metric': 'totalUiFrame.average', 'value': 4166},
+  ],
+  'bar': <Map<String, Object?>>[
+    <String, Object?>{'metric': 'preroll_frame.average', 'value': 60.5},
+    <String, Object?>{'metric': 'preroll_frame.outlierAverage', 'value': 1400},
+    <String, Object?>{'metric': 'preroll_frame.outlierRatio', 'value': 20.2},
+    <String, Object?>{'metric': 'preroll_frame.noise', 'value': 0.85},
+    <String, Object?>{'metric': 'apply_frame.average', 'value': 80.0},
+    <String, Object?>{'metric': 'apply_frame.outlierAverage', 'value': 200.6},
+    <String, Object?>{'metric': 'apply_frame.outlierRatio', 'value': 2.5},
+    <String, Object?>{'metric': 'apply_frame.noise', 'value': 0.4},
+    <String, Object?>{'metric': 'drawFrameDuration.average', 'value': 2058.9},
+    <String, Object?>{
+      'metric': 'drawFrameDuration.outlierAverage',
+      'value': 24000,
+    },
+    <String, Object?>{
+      'metric': 'drawFrameDuration.outlierRatio',
+      'value': 12.05,
+    },
+    <String, Object?>{'metric': 'drawFrameDuration.noise', 'value': 0.34},
+    <String, Object?>{'metric': 'totalUiFrame.average', 'value': 4166},
+  ],
+};
+
+final Map<String, List<Map<String, Object?>>> testBenchmarkResults2 =
+    <String, List<Map<String, Object?>>>{
+  'foo': <Map<String, Object?>>[
+    <String, Object?>{'metric': 'preroll_frame.average', 'value': 65.5},
+    <String, Object?>{'metric': 'preroll_frame.outlierAverage', 'value': 1410},
+    <String, Object?>{'metric': 'preroll_frame.outlierRatio', 'value': 20.0},
+    <String, Object?>{'metric': 'preroll_frame.noise', 'value': 1.5},
+    <String, Object?>{'metric': 'apply_frame.average', 'value': 50.0},
+    <String, Object?>{'metric': 'apply_frame.outlierAverage', 'value': 100.0},
+    <String, Object?>{'metric': 'apply_frame.outlierRatio', 'value': 2.55},
+    <String, Object?>{'metric': 'apply_frame.noise', 'value': 0.9},
+    <String, Object?>{'metric': 'drawFrameDuration.average', 'value': 2000.0},
+    <String, Object?>{
+      'metric': 'drawFrameDuration.outlierAverage',
+      'value': 20000
+    },
+    <String, Object?>{
+      'metric': 'drawFrameDuration.outlierRatio',
+      'value': 11.05
+    },
+    <String, Object?>{'metric': 'drawFrameDuration.noise', 'value': 1.34},
+    <String, Object?>{'metric': 'totalUiFrame.average', 'value': 4150},
+  ],
+  'bar': <Map<String, Object?>>[
+    <String, Object?>{'metric': 'preroll_frame.average', 'value': 65.5},
+    <String, Object?>{'metric': 'preroll_frame.outlierAverage', 'value': 1410},
+    <String, Object?>{'metric': 'preroll_frame.outlierRatio', 'value': 20.0},
+    <String, Object?>{'metric': 'preroll_frame.noise', 'value': 1.5},
+    <String, Object?>{'metric': 'apply_frame.average', 'value': 50.0},
+    <String, Object?>{'metric': 'apply_frame.outlierAverage', 'value': 100.0},
+    <String, Object?>{'metric': 'apply_frame.outlierRatio', 'value': 2.55},
+    <String, Object?>{'metric': 'apply_frame.noise', 'value': 0.9},
+    <String, Object?>{'metric': 'drawFrameDuration.average', 'value': 2000.0},
+    <String, Object?>{
+      'metric': 'drawFrameDuration.outlierAverage',
+      'value': 20000
+    },
+    <String, Object?>{
+      'metric': 'drawFrameDuration.outlierRatio',
+      'value': 11.05
+    },
+    <String, Object?>{'metric': 'drawFrameDuration.noise', 'value': 1.34},
+    <String, Object?>{'metric': 'totalUiFrame.average', 'value': 4150},
+  ],
+};
+
+final Map<String, List<Map<String, Object?>>> expectedBenchmarkDelta =
+    <String, List<Map<String, Object?>>>{
+  'foo': <Map<String, Object?>>[
+    <String, Object?>{
+      'metric': 'preroll_frame.average',
+      'value': 65.5,
+      'delta': 5.0
+    },
+    <String, Object?>{
+      'metric': 'preroll_frame.outlierAverage',
+      'value': 1410.0,
+      'delta': 10.0,
+    },
+    <String, Object?>{
+      'metric': 'preroll_frame.outlierRatio',
+      'value': 20.0,
+      'delta': -0.1999999999999993,
+    },
+    <String, Object?>{
+      'metric': 'preroll_frame.noise',
+      'value': 1.5,
+      'delta': 0.65,
+    },
+    <String, Object?>{
+      'metric': 'apply_frame.average',
+      'value': 50.0,
+      'delta': -30.0,
+    },
+    <String, Object?>{
+      'metric': 'apply_frame.outlierAverage',
+      'value': 100.0,
+      'delta': -100.6,
+    },
+    <String, Object?>{
+      'metric': 'apply_frame.outlierRatio',
+      'value': 2.55,
+      'delta': 0.04999999999999982,
+    },
+    <String, Object?>{
+      'metric': 'apply_frame.noise',
+      'value': 0.9,
+      'delta': 0.5,
+    },
+    <String, Object?>{
+      'metric': 'drawFrameDuration.average',
+      'value': 2000.0,
+      'delta': -58.90000000000009,
+    },
+    <String, Object?>{
+      'metric': 'drawFrameDuration.outlierAverage',
+      'value': 20000.0,
+      'delta': -4000.0,
+    },
+    <String, Object?>{
+      'metric': 'drawFrameDuration.outlierRatio',
+      'value': 11.05,
+      'delta': -1.0,
+    },
+    <String, Object?>{
+      'metric': 'drawFrameDuration.noise',
+      'value': 1.34,
+      'delta': 1.0,
+    },
+    <String, Object?>{
+      'metric': 'totalUiFrame.average',
+      'value': 4150.0,
+      'delta': -16.0,
+    },
+  ],
+  'bar': <Map<String, Object?>>[
+    <String, Object?>{
+      'metric': 'preroll_frame.average',
+      'value': 65.5,
+      'delta': 5.0,
+    },
+    <String, Object?>{
+      'metric': 'preroll_frame.outlierAverage',
+      'value': 1410.0,
+      'delta': 10.0,
+    },
+    <String, Object?>{
+      'metric': 'preroll_frame.outlierRatio',
+      'value': 20.0,
+      'delta': -0.1999999999999993,
+    },
+    <String, Object?>{
+      'metric': 'preroll_frame.noise',
+      'value': 1.5,
+      'delta': 0.65,
+    },
+    <String, Object?>{
+      'metric': 'apply_frame.average',
+      'value': 50.0,
+      'delta': -30.0,
+    },
+    <String, Object?>{
+      'metric': 'apply_frame.outlierAverage',
+      'value': 100.0,
+      'delta': -100.6,
+    },
+    <String, Object?>{
+      'metric': 'apply_frame.outlierRatio',
+      'value': 2.55,
+      'delta': 0.04999999999999982,
+    },
+    <String, Object?>{
+      'metric': 'apply_frame.noise',
+      'value': 0.9,
+      'delta': 0.5,
+    },
+    <String, Object?>{
+      'metric': 'drawFrameDuration.average',
+      'value': 2000.0,
+      'delta': -58.90000000000009,
+    },
+    <String, Object?>{
+      'metric': 'drawFrameDuration.outlierAverage',
+      'value': 20000.0,
+      'delta': -4000.0,
+    },
+    <String, Object?>{
+      'metric': 'drawFrameDuration.outlierRatio',
+      'value': 11.05,
+      'delta': -1.0,
+    },
+    <String, Object?>{
+      'metric': 'drawFrameDuration.noise',
+      'value': 1.34,
+      'delta': 1.0,
+    },
+    <String, Object?>{
+      'metric': 'totalUiFrame.average',
+      'value': 4150.0,
+      'delta': -16.0,
+    },
+  ],
+};
diff --git a/packages/web_benchmarks/test/src/benchmark_result_test.dart b/packages/web_benchmarks/test/src/benchmark_result_test.dart
index 18765d00646..65adee8556a 100644
--- a/packages/web_benchmarks/test/src/benchmark_result_test.dart
+++ b/packages/web_benchmarks/test/src/benchmark_result_test.dart
@@ -10,8 +10,8 @@ void main() {
     test('$BenchmarkResults', () {
       final Map<String, Object?> data = <String, Object?>{
         'foo': <Map<String, Object?>>[
-          <String, Object?>{'metric': 'foo.bar', 'value': 12.34},
-          <String, Object?>{'metric': 'foo.baz', 'value': 10},
+          <String, Object?>{'metric': 'foo.bar', 'value': 12.34, 'delta': -0.2},
+          <String, Object?>{'metric': 'foo.baz', 'value': 10, 'delta': 3.3},
         ],
         'bar': <Map<String, Object?>>[
           <String, Object?>{'metric': 'bar.foo', 'value': 1.23},
@@ -27,11 +27,14 @@ void main() {
       expect(fooBenchmarks.length, 2);
       expect(fooBenchmarks[0].metric, 'foo.bar');
       expect(fooBenchmarks[0].value, 12.34);
+      expect(fooBenchmarks[0].delta, -0.2);
       expect(fooBenchmarks[1].metric, 'foo.baz');
       expect(fooBenchmarks[1].value, 10);
+      expect(fooBenchmarks[1].delta, 3.3);
       expect(barBenchmarks.length, 1);
       expect(barBenchmarks[0].metric, 'bar.foo');
       expect(barBenchmarks[0].value, 1.23);
+      expect(barBenchmarks[0].delta, isNull);
 
       expect(benchmarkResults.toJson(), data);
     });
@@ -39,12 +42,14 @@ void main() {
     test('$BenchmarkScore', () {
       final Map<String, Object?> data = <String, Object?>{
         'metric': 'foo',
-        'value': 1.234
+        'value': 1.234,
+        'delta': -0.4,
       };
 
       final BenchmarkScore score = BenchmarkScore.parse(data);
       expect(score.metric, 'foo');
       expect(score.value, 1.234);
+      expect(score.delta, -0.4);
 
       expect(score.toJson(), data);
     });